Dickkopf 4 (DKK4) acts on Wnt/ß-catenin pathway by influencing ß-catenin in hepatocellular carcinoma.

Deregulation of Wnt/ß-catenin pathway is a hallmark of major gastrointestinal cancers including hepatocellular carcinoma (HCC). The oncogenic role of ß-catenin is well defined but reasons for its accumulation in HCC remain unclear. Dickkopf 4 (DKK4) acts as a negative regulator of Wnt/ß-catenin pathway but its functional role in liver carcinogenesis has not been studied. We investigated the role of DKK4 in ß-catenin regulation in HCC. Reduced expression of DKK4 was found in 47% (38/81) of HCC, as measured by quantitative real time PCR. Ectopic expression of DKK4 in two HCC cell lines, PLC/PRF/5 (PLC) and MHCC97L (97L), attenuated ß-catenin responsive luciferase activity, and decreased both ß-catenin and cyclin D1 protein levels. To study the effect of DKK4 on cell growth and tumourigenicity, two stable HCC cell lines were established from PLC and 97L cells. Functional assays demonstrated that overexpression of DKK4 hampered cell proliferation, reduced colony formation and retarded cell migration. When DKK4-expressing 97L stable cells were used to induce tumour xenografts in nude mice (n=8), reduction in tumour sizes was observed (P=0.027). Furthermore, immunohistochemical studies showed that decreased expression of DKK4 was associated with ß-catenin accumulation in HCC tissues. Additionally, inhibition of the proteasome using specific inhibitor in DKK4-expressing 97L stable cells masked the effect of ß-catenin. Our findings suggest a potential tumour suppressive role of DKK4 as well as that of an important regulator of HCC.

Association of CD247 with systemic lupus erythematosus in Asian populations.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. CD247 (CD3Z, TCRZ) plays a vital role in antigen recognition and signal transduction in antigen-specific immune responses, and is known to be involved in SLE pathogenesis. Weak disease association was reported for genetic variants in this gene in Caucasian studies for SLE, Crohn's disease and systemic sclerosis, but its role as a genetic risk factor was never firmly established. METHODS: In this study, using a collection of 612 SLE patients and 2193 controls of Chinese ethnicity living in Hong Kong in a genome-wide study, single nucleotide polymorphisms (SNPs) in and around CD247 were identified as being associated with SLE. The two most significant SNPs in this locus were selected for further replication using TaqMan genotyping assay in 3339 Asian patients from Hong Kong, Mainland China, and Thailand, as well as 4737 ethnically and geographically matched controls. RESULTS: The association of CD247 with SLE in Asian populations was confirmed (rs704853: odds ratio [OR] = 0. 81, p = 2.47 × 10(-7); rs858543: OR = 1.10, p = 0.0048). Patient-only analysis suggested that rs704853 is also linked to oral ulcers, hematologic disorders and anti-double-stranded DNA (dsDNA) antibody production. CONCLUSION: A significant association between variants in CD247 and SLE was demonstrated in Asian populations. Understanding the involvement of CD247 in SLE may shed new light on disease mechanisms and development of new treatment paradigms.

Epigenetic repression of E-cadherin expression by hepatitis B virus x antigen in liver cancer.

Loss of E-cadherin is associated with acquisition of metastatic capacity. Numerous studies suggest that histone deacetylation and/or hypermethylation of CpG islands in E-cadherin gene (CDH1) are major mechanisms responsible for E-cadherin silencing in different tumors and cancer cell lines. The hepatitis B virus (HBV)-encoded X antigen, HBx, contributes importantly to the development of hepatocellular carcinoma using multiple mechanisms. Experiments were designed to test if in addition to CDH1 hypermethylation HBx promotes epigenetic modulation of E-cadherin transcriptional activity through histone deacetylation and miR-373. The relationships between HBx, E-cadherin, mSin3A, Snail-1 and miR-373 were evaluated in HBx expressing (HepG2X) and control (HepG2CAT) cells by western blotting, immunoprecipitation (IP), chromatin IP as well as by immunohistochemical staining of liver and tumor tissue sections from HBV-infected patients. In HepG2X cells, decreased levels of E-cadherin and elevated levels of mSin3A and Snail-1 were detected. Reciprocal IP with anti-HBx and anti-mSin3A demonstrated mutual binding. Furthermore, HBx-mSin3A colocalization was detected by immunofluorescent staining. HBx downregulated E-cadherin expression by the recruitment of the mSin3A/histone deacetylase complex to the Snail-binding sites in human CDH1. Histone deacetylation inhibition by Trichostatin-A treatment restored E-cadherin expression. Mir-373, a positive regulator of E-cadherin expression, was downregulated by HBx in HepG2X cells and tissue sections from HBV-infected patients. Thus, histone deacetylation of CDH1 and downregulation of miR-373, together with the previously demonstrated hypermethylation of CDH1 by HBx, may be important for the understanding of HBV-related carcinogenesis.

Two missense variants in UHRF1BP1 are independently associated with systemic lupus erythematosus in Hong Kong Chinese.

UHRF1BP1 encodes a highly conserved protein with unknown function. Previously, a coding variant in this gene was found to be associated with systemic lupus erythematosus (SLE) in populations of European ancestry (rs11755393, R454Q, P=2.22 x 10⁻8, odds ratio=1.17). In this study, by a combination of genome-wide study and replication involving a total of 1230 patients and 3144 controls, we confirmed the association of this coding variant to SLE in Hong Kong Chinese. We also identified another coding variant in this gene that independently contributes to SLE susceptibility (rs13205210, M1098T, P=4.44 x 10⁻9, odds ratio=1.49). Cross-population confirmation establishes the involvement of this locus in SLE and indicates that distinct alleles are contributing to disease susceptibility.

Association of BANK1 and TNFSF4 with systemic lupus erythematosus in Hong Kong Chinese.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. Recently, single nucleotide polymorphisms (SNPs) in BANK1 and TNFSF4 have been shown to be associated with SLE in Caucasian populations, but it is not known whether they are also involved in the disease in other ethnic groups. Recent data from our genome-wide association study (GWAS) for 314 SLE cases and 920 controls collected in Hong Kong identified SNPs in and around BANK1 and TNFSF4 to be associated with SLE risk. On the basis of the results of the reported studies and our GWAS, SNPs were selected for further genotyping in 949 SLE patients (overlapping with the 314 cases in our GWAS) and non-overlapping 1042 healthy controls. We confirmed the associations of BANK1 and TNFSF4 with SLE in Chinese (BANK1, rs3733197, odds ratio (OR)=0.84, P=0.021; BANK1, rs17266594, OR=0.61, P=4.67 x 10(-9); TNFSF4, rs844648, OR=1.22, P=2.47 x 10(-3); TNFSF4, rs2205960, OR=1.30, P=2.41 x 10(-4)). Another SNP located in intron 1 of BANK1, rs4522865, was separately replicated by Sequenom in 360 cases and 360 controls and was also confirmed to be associated with SLE (OR=0.725, P=2.93 x 10(-3)). Logistic regression analysis showed that rs3733197 (A383T in ankyrin domain) and rs17266594 (a branch point-site SNP) from BANK1 had independent contributions towards the disease association (P=0.037 and 6.63 x 10(-8), respectively). In TNFSF4, rs2205960 was associated with SLE independently from the effect of rs844648 (P=6.26 x 10(-3)), but not vice versa (P=0.55). These findings suggest that multiple independent genetic variants may be present within the gene locus, which exert their effects on SLE pathogenesis through different mechanisms.

Hepatocyte-specific activation of NF-kappaB does not aggravate chemical hepatocarcinogenesis in transgenic mice.

The NF-kappaB signalling pathway plays important roles in liver organogenesis and carcinogenesis. Mouse embryos deficient in IKKbeta die in mid-gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF-kappaB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF-kappaB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKbeta was expressed in a hepatocyte-specific manner. Using electrophoretic mobility shift assay, we documented increased NF-kappaB activities and up-regulated levels of NF-kappaB downstream target genes, Bcl-xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF-kappaB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild-type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF-kappaB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF-kappaB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF-kappaB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases.

Imaging features of hepatic angiomyolipomas.

We review the imaging appearances of hepatic angiomyolipomas in patients with and without tuberous sclerosis. Sporadic hepatic angiomyolipomas have a varied appearance because of the inconstant proportion of fat, making confident imaging diagnosis difficult and necessitating biopsy in many cases. In patients with tuberous sclerosis, hepatic angiomyolipomas have a more consistent imaging appearance and, together with other features of the syndrome, can be more easily diagnosed. Preoperative diagnosis helps obviate unnecessary surgery.

Living donor versus deceased donor liver transplantation for early irresectable hepatocellular carcinoma.

BACKGROUND: Hypothetical studies that favour living donor liver transplantation (LDLT) for early hepatocellular carcinoma (HCC) assumed a comparable outcome after LDLT and deceased donor liver transplantation (DDLT). The aim of this study was to compare the outcome after LDLT with that after DDLT, and to identify factors that might account for any differences. METHODS: The study included 60 patients who met the radiological Milan or University of California at San Francisco (UCSF) criteria and underwent LDLT (43 patients) or DDLT (17). RESULTS: The LDLT group had fewer incidental tumours and a lower rate of pretransplant transarterial chemoembolization but a higher rate of salvage transplantation. Waiting time was shorter and graft weight to standard liver weight (GW : SLW) ratio was lower in this group. The perioperative course, and histopathological tumour size, number, grade and stage were comparable. Median follow-up was 33 (range 4-120) months. The cumulative 5-year recurrence rate was 29 per cent in the LDLT group and 0 per cent in the DDLT group (P = 0.029). A GW : SLW ratio of 0.6 or less, salvage transplantation, three or more tumour nodules, microscopic vascular invasion, and pathological stage beyond the Milan or UCSF criteria were significant confounding risk factors. Multivariable analysis identified salvage transplantation (relative risk 5.16 (95 per cent confidence interval (c.i.) 1.48 to 18.02); P = 0.010) and pathological stage beyond the UCSF criteria (relative risk 4.10 (95 per cent c.i. 1.02 to 16.48); P = 0.047) as independent predictors of recurrence. CONCLUSION: Despite standard radiological selection criteria based on number and size, patients who underwent LDLT for HCC had more recurrence because of selection bias for other clinical characteristics.

Hepatic necroinflammation and fibrosis in patients with genotypes Ba and C, core-promoter and precore mutations.

SUMMARY: The role of infection with hepatitis B virus (HBV) genotypes on liver histology is largely unknown. The aim of study was to investigate the relationships between HBV genotypes (B, C), core-promoter (CP) and precore mutants and liver histology in 66 patients. Liver biopsies were scored by histologic activity index (HAI). HBV genotypes were determined by enzyme-linked immunosorbent assay (ELISA). Eighteen (27.3%) and 48 patients (72.7%) had genotype B (all were subtype Ba) and C, respectively. Forty-seven (71.2%) and 27 (40.9%) had CP and precore mutations, respectively. Patients with genotype C compared with subtype Ba had higher median scores of HAI-necroinflammation (HAI-NI) (7 vs 3), HAI-fibrosis (HAI-F) (1 vs 0) and total HAI (8.5 vs 3) (all P < 0.03). Patients with CP mutations compared with wild-type had higher median scores of HAI-NI (7 vs 3), HAI-F (3 vs 0) and total HAI (9 vs 3) (all P < 0.03). Forty patients (83.5%) with genotype C had CP mutations. Age and alanine aminotransferase levels were positively correlated with HAI scores while albumin levels were negatively correlated (P < 0.01 for all, except albumin levels and HAI-F, P = 0.08). There was no association between precore mutations and HAI scores. Multivariate analysis indicated that higher alanine aminotransferase (ALT) levels were associated with higher HAI scores (P < 0.04) and CP mutations were associated with higher HAI-NI (P = 0.034), but not with HAI-F score (P = 0.3). CP mutations were associated with more severe necroinflammation. The association between genotype C and poor histology was probably because of the association between genotype C and CP mutations.

Prognostic significance of serum vascular endothelial growth factor and endostatin in patients with hepatocellular carcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF) and endostatin stimulate and inhibit tumour angiogenesis respectively. Recent studies have demonstrated the prognostic value of serum levels of both VEGF and endostatin in patients with various types of cancer. Their significance in patients with hepatocellular carcinoma (HCC) remains unclear. METHODS: Serum VEGF and endostatin levels were measured by enzyme immunoassay in 108 patients with HCC before surgical resection and in 20 healthy controls. Preoperative serum VEGF and endostatin levels were correlated with clinicopathological features and long-term survival. RESULTS: Serum VEGF levels in patients with HCC were significantly higher than those in controls, but serum levels of endostatin were similar in the two groups. High serum levels of VEGF, but not endostatin, were significantly associated with venous invasion and advanced tumour stage. Patients with a serum VEGF level higher than median (over 245.0 pg/ml) had significantly worse overall and disease-free survival than those with a lower level (P = 0.012 and P = 0.022 respectively). On multivariate analysis, serum VEGF level was an independent prognostic factor (hazard ratio 1.86 (95 per cent confidence interval 1.10 to 3.92); P = 0.032). Serum endostatin levels did not have significant prognostic influence on overall or disease-free survival. CONCLUSION: A high serum level of VEGF is a predictor of poor outcome after resection of HCC. Serum VEGF, but not endostatin, may be a useful prognostic marker in patients with HCC.

Liver graft-versus-host disease after donor lymphocyte infusion for relapses of hematologic malignancies post allogeneic hematopoietic stem cell transplantation.

Graft-versus-host disease (GVHD) is the commonest complication after donor lymphocyte infusion (DLI). In 19 patients undergoing DLI for relapses of hematologic malignancies post hematopoietic stem cell transplantation (HSCT), 11 developed GVHD, of whom nine had isolated liver involvement, and two had liver and skin involvement. The clinical diagnosis of liver GVHD was hepatitic in six patients (55%) and classical in five patients (45%). Patients with GVHD post-DLI showed a different clinical pattern when compared to a cohort of 106 cases of GVHD post-HSCT, in having significantly more isolated liver involvement (9/11 vs 17/106, P<0.001), and less skin (2/11 vs 80/106, P<0.001) and gut (0/11 vs 28/106, P<0.001) involvement. However, liver GVHD post-DLI and post-HSCT had comparable patient characteristics, underlying diseases, clinical subtypes (classical and hepatitic) and response to treatment.

Different presentation of hepatitis B-related hepatocellular carcinoma in a cohort of 1863 young and old patients - implications for screening.

AIM: To compare the clinico-pathological features of hepatitis B virus-related hepatocellular carcinoma in young and old patients. METHODS: The clinico-pathological characteristics of hepatitis B virus-related hepatocellular carcinoma were compared in 1863 consecutive patients (121 patients, 40 years) seen at a single institution over the last 13 years. RESULTS: Young patients presented more often with pain (P < 0.0001), hepatomegaly (P = 0.01) and ruptured hepatocellular carcinoma (P = 0.02), whereas old patients presented with ankle oedema (P = 0.001), ascites (P = 0.002) and by routine screening (P = 0.035). Liver function, Child-Pugh grading and indocyanine green test were better preserved in young patients. They also had a higher alpha-foetoprotein concentration (P = 0.001), larger tumour size (P = 0.001) and more frequent metastasis (P = 0.008), but a similar surgical resection rate (33.6% vs. 28%), to old patients. There was no difference between the two groups in the overall post-resection survival rate, but there was a shorter survival in young patients with unresectable disease (3.6 months vs. 4.6 months, P = 0.004). Young patients with hepatocellular carcinoma often show a later presentation, but a higher resectability rate and similar survival rates, than old patients. The screening programme should include young hepatitis B virus carriers, even in the absence of cirrhosis.

Cholestatic jaundice caused by sequential carbimazole and propylthiouracil treatment for thyrotoxicosis.

A 36-year-old Chinese man presented to the Queen Mary Hospital in August 1999 with a 2-week history of jaundice due to propylthiouracil treatment for thyrotoxicosis. He had previously received carbimazole but had developed an urticarial skin rash after 2 weeks of treatment. The patient developed liver failure and fulminant pneumonitis shortly after hospital admission. Despite receiving treatment with broad-spectrum antibiotics and intravenous immunoglobulin, he died 11 days after the onset of the respiratory symptoms. Postmortem examination using electron microscopy showed typical glycogen bodies within the cytoplasm of the hepatocytes, which corresponded to eosinophilic cytoplasmic inclusion bodies visible under light microscopy. Immunohistochemical studies of the inclusion bodies were positive for carcinoembryonic antigen and albumin, and negative for fibrinogen, complement protein C3, immunoglobulins G, M, and A, alpha-fetoprotein, and alpha-1-antitrypsin. This is the first report of a patient who received two sequential antithyroid drugs and developed predominate cholestasis with unique histological features. Extreme caution should be taken when a patient develops allergy to one type of antithyroid drug, because cross-reactivity may develop to the other type.

Emergency living related liver transplantation for fulminant reactivation of hepatitis B virus after unrelated marrow transplantation.

We report a unique case of emergency living related donor orthotopic liver transplantation (OLT) for late fulminant reactivation of hepatitis B virus (HBV) after matched unrelated bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Cessation of lamivudine after BMT for HBV positive patients may carry risks of late fatal HBV reactivation. Similar to fulminant HBV reactivation in the general population, OLT under resumption of lamivudine can be life saving. In our case, concomitantly molecular relapse of CML at the time of liver failure was also cleared by OLT, possibly via a 'liver-graft vs. leukemia' effect. Liver rejection (graft vs. graft disease) was mild due to inherent immunocompromise of the marrow graft. Hence BMT recipients in stable remission should not be denied the opportunity for life-saving solid organ transplantation. A choice of marrow and liver donors with innate HBV immunity may be needed to give the additional advantage of long-term HBV clearance.

Effects of the intermittent Pringle manoeuvre on hepatic gene expression and ultrastructure in a randomized clinical study.

BACKGROUND: The intermittent Pringle manoeuvre during hepatectomy results in a better clinical outcome when the accumulated ischaemia time is less than 120 min. The aim of this study was to investigate hepatic gene expression related to microcirculatory modulation and ultrastructural changes in patients having the intermittent Pringle manoeuvre. METHODS: Forty patients who underwent hepatectomy for liver tumours were randomly assigned to liver transection with intermittent Pringle manoeuvre (Pringle group, n = 20) or without the manoeuvre (control group, n = 20). The clinical data and hepatic expression of endothelin (ET) 1 and endothelial nitric oxide synthase (eNOS) combined with liver ultrastructure were compared. RESULTS: The Pringle manoeuvre resulted in less blood loss (8.9 versus 12.4 ml/cm(2); P = 0.034), a shorter transection time (2.7 versus 4.1 min/cm(2); P = 0.015) and a lower serum bilirubin level on postoperative day 2 (26 versus 35 microm/l; P = 0.04). The hepatic messenger RNA content of ET-1 decreased by 38 per cent of the basal level in the Pringle group, whereas it increased by 28 per cent in the control group (P = 0.026). More patients in the control group showed swelling of mitochondria in hepatocytes and disruption of sinusoidal lining cells (12 of 20 patients versus three of 20 in the Pringle group; P = 0.008). CONCLUSION: The intermittent Pringle manoeuvre results in less disturbance of the hepatic microcirculation and better preservation of liver sinusoids after hepatectomy.

Surgical complications and outcome of pediatric liver transplantation in Hong Kong.

PURPOSE: The aim of this study was to analyze the early and late results of pediatric liver transplantation, with particular reference to complications that required surgical or radiologic intervention. METHODS: The records and code sheets of children who underwent liver transplantation in the authors' institution between September 1993 and December 2001 were reviewed. RESULTS: Twenty-nine children (16 boys and 13 girls) underwent 31 liver transplantations (23 living donor, 8 cadaveric donor) during the study period. The ages of the children ranged from 4 months to 132 months (median, 16 months). Eighteen children had complications that required surgical or radiologic interventional procedures. Complications included, among others, hepatic vein thrombosis (n = 1, 3%), hepatic vein stenosis (n = 2, 7%), portal vein thrombosis (n = 2, 7%), biliary stricture (n = 3, 10%), bile leakage (n = 2, 7%), hepatic artery pseudoaneurysm (n = 1, 3%), jejuno-jejunostomy leakage (n = 1, 3%), graft hepatitis (n = 1, 3%), and posttransplant lymphoproliferative disorder (n = 2, 7%). In addition, 6 children (21%) suffered from intraabdominal bleeding from a variety of causes. After appropriate interventions, at a median follow-up of 38 months (range, 1 to 96 months), patient and graft survival rates were 79% and 74%, respectively. The retransplantation rate was only 7%. There was no incidence of hepatic artery thrombosis. All living donors remain alive and well. CONCLUSIONS: Complications are inevitable in pediatric liver transplantation. However, with timely recognition and active intervention, a good outcome can be achieved.

Hepatic resection for colorectal liver metastases: prospective study.

OBJECTIVE: To assess the operative and long-term survival outcomes of hepatic resection for colorectal liver metastases during an 11-year period in a tertiary referral centre in Hong Kong. DESIGN: Prospective study. SETTING: University teaching hospital, Hong Kong. SUBJECTS AND METHODS: Between January 1989 and December 1999, 72 patients underwent hepatic resection for colorectal liver metastases. Clinical, pathological, and outcome data were prospectively collected and analysed. Factors affecting long-term survival were also evaluated. RESULTS: Twenty-five (34.7%) patients were found to have synchronous hepatic metastasis at the time of colorectal resection. Fifty-two (72.2%) patients underwent major hepatic resection. The operative morbidity and hospital mortality rates were 19% and 4%, respectively. The 5-year survival rate after hepatectomy was 31.9%. The median disease-free survival and median overall cumulative survival were 18.5 months and 30.8 months, respectively. On multivariate analysis, a high preoperative serum carcinoembryonic antigen level (>200 ng/mL) and tumour involvement of the resection margin at histology were the two independent risk factors that adversely affected survival outcome. CONCLUSION: Hepatic resection for colorectal liver metastases can be performed safely, with minimal operative mortality and acceptable morbidity, and results in satisfactory survival. High preoperative serum carcinoembryonic antigen level and histological involvement of resection margin by cancer adversely affect the survival outcome.